An ounce of prevention may be worth a pound of cure, but if you're vomiting into a cruise ship toilet then that pound of cure is worth something too. Enter medications. A ship's doctor can help you out with any kind of medication you need. But if you know you're prone to motion sickness, then do yourself a favor and bring some of these meds along with you. There isn't one single cure-all for seasickness, so you'll have to experiment until you find something that works for you.

­There are two ways to go with seasickness medications. Some work only on the nausea, while others try and minimize the motion effect. Scopolamine is the most popular drug for motion sickness and is only available by prescription. It blocks the vestibular organs from sending messages to the central nervous system. It can be delivered orally, by injection or as a transdermal patch you wear on your skin. The patch lasts about three days. You'll need to take scopolamine before you feel symptoms, and side effects include dry mouth, nose and throat, blurred vision and drowsiness.

Antihistamines are another alternative. They work by depressing the vomit center of the brain. They're available as over-the-counter (OTC) or prescription-only and include:

Promethazine (Phenergan, Prorex, Anergan 50) -- This prescription-only decreases nausea, but is the most sedating.

Dimenhydrinate (Dramamine, Triptone, Gravol) -- You need to take this OTC every four to eight hours.

Meclizine (Bonine and Dramamine II) -- This OTC has a once-a-day dosage and is less sedating.

Cyclizine (Marezine) -- The dosage for this OTC is required every four to six hours.

Diphenhydramine (Benadryl) -- This OTC causes significant drowsiness.

Antihistamines all make you somewhat drowsy and impair your motor skills. The effect is increased with alcohol, so you shouldn't hit a booze cruise if you plan on taking these drugs.

There are also acupressure bracelets you can wear to help relieve nausea, but their effectiveness is subject to debate. The bracelet, or band, applies pressure to the palm side of your wrist to an acupuncture point called pericardium 6, or P6. The bands are also used by chemotherapy patients and pregnant women. Since no drug is administered, it's the safest way to go if it works, and it allows you to indulge in a guilt-free cocktail or two.

Habituation is another treatment used by those who suffer from motion sickness. It involves exposing yourself to the trigger that causes motion sickness -- in this case, going out on a boat -- until you become used to it. The theory is that over time the repetitive exposure to the stimuli will help to decrease the response, or the sickness. Balance training through yoga and meditation are a couple of other alternative therapies you can try. One cruiser from a Web forum suggests focusing the meditation on the comforting feelings that a baby gets from rocking back and forth. Since it's very unusual for a child under two years old to suffer from motion sickness, there may be something to this therapy. If you're set on cruising or boating and have a tendency to get motion sickness, try every tip and trick you can and experiment with a variety of preventative medications to find one that works. The high seas await you.